Unified study of glass and jamming rheology in soft particle systems
King's College London
Mon, Mar. 18th 2013, 14:30
Salle Claude Itzykson, Bât. 774, Orme des Merisiers
noindent Authors: Atsushi Ikeda, Ludovic Berthier, and Peter Sollich \ \
Abstract: We explore numerically the shear rheology of soft repulsive particles at large volume fraction. The interplay between viscous dissipation and thermal motion results in multiple rheological regimes encompassing Newtonian, shear-thinning and yield stress regimes near the ``colloidal'' glass transition when thermal fluctuations are important, crossing over to qualitatively similar regimes near the ``jamming''
transition when dissipation dominates. In the crossover regime, glass and jamming sectors coexist and give complex flow curves. Although glass and jamming limits are characterized by similar macroscopic flow curves, we show that they occur over distinct time and stress scales and correspond to distinct microscopic dynamics. We propose a simple rheological model describing the glass to jamming crossover in the flow curves, and discuss the experimental implications of our results. Time permitting a systematic comparison of the model to data for a number of paradigmatic experimental systems will be described.